Lawn mower

Abstract

To provide a mower that can stably travel on a sloped or stepped ridge.SOLUTION: A mower mows grass while traveling on a ridge, and comprises: a machine body; a traveling part; and a link mechanism comprising a first link arm including a first arm part of which one end is rotatably connected to the machine body via a first rotation shaft, and of which the other end is rotatably connected to the traveling part, and a second link arm including a third arm part of which one end is rotatably connected to the machine body via a second rotation shaft, of which the other end is rotatably connected to the traveling part, and arranged in front of the first arm part, and for moving the traveling part with respect to the machine body. When the first arm part is rotated around the first rotation shaft, the first rotation shaft is located between an upper rotation position and a lower rotation position of the other end of the first arm part in a height direction.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a lawn mower.

Background Art

[0002] Conventionally, in order to remove weeds and the like growing on the top surface or side surface of a ridge, a lawn mower is used to regularly mow the grass on the ridge. Patent Document 1 describes a self-propelled lawn mower that performs mowing operations on the top surface and side surface while traveling on the ridge by remote control via wireless communication. The lawn mowers described in Patent Documents 1 and 2 include a traveling unit having a pair of left and right crawlers, and a cutting blade unit having a horizontal cutting blade and an inclined cutting blade at the front part of the machine body. By using the traveling unit having a pair of left and right crawlers to travel back and forth on the ridge, it is possible to remove weeds and the like growing on the top surface and side surface by using the cutting blade unit having a horizontal cutting blade and an inclined cutting blade.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] Since the configurations of the lawn mowers described in Patent Documents 1 and 2 are configured to move only back and forth by a traveling unit having a pair of left and right crawlers, for example, when there is an inclination or step on the top surface of a ridge, there is a problem that the lawn mower is likely to lose its balance.

[0005] One of the problems of an embodiment of the present invention is to provide a lawn mower that can stably travel even on a ridge with an inclination or step.

Means for Solving the Problems

[0006] A lawnmower according to one embodiment of the present invention is a lawnmower that cuts grass while traveling on a ridge, and comprises a machine body, a traveling section, a first link arm including a first arm portion with one end rotatably connected to the machine body on a first pivot axis and the other end rotatably connected to the traveling section, and a second link arm including a third arm portion with one end rotatably connected to the machine body on a second pivot axis and the other end rotatably connected to the traveling section, and which is positioned in front of the first arm portion, and a link mechanism for moving the traveling section relative to the machine body, wherein when the first arm portion is rotated about the first pivot axis as the pivot point, the first pivot axis is located in the height direction between the upper rotation position and the lower rotation position of the other end of the first arm portion.

[0007] The first link arm may have a second arm portion extending in a direction other than the first direction from one end connected to a first pivot axis of the first arm portion extending in a first direction, and the second link arm may have a fourth arm portion extending in a direction other than the second direction from one end connected to a second pivot axis of the third arm portion extending in a second direction.

[0008] The first link arm and the second link arm may have a link plate connecting them.

[0009] The system may further include an actuator, one end of which is connected to the machine body and the other end of which is connected to either the first link arm or the second link arm, and which serves as a power source for moving the running section relative to the machine body via the link mechanism.

[0010] One end is connected to the machine body, and the other end is connected to the first link arm or the second link arm to which the actuator is not connected. The system may further include auxiliary means for assisting the movement of the traveling section relative to the machine body by the actuator.

[0011] The actuator may be connected to the first link arm, and the auxiliary means may be connected to the second link arm. [Effects of the Invention]

[0012] According to one embodiment of the present invention, a lawnmower can be provided that can travel stably even on ridges with slopes or steps. [Brief explanation of the drawing]

[0013] [Figure 1] This is a plan view showing the configuration of a lawnmower according to one embodiment of the present invention. [Figure 2] This is a left side view showing the configuration of a lawnmower according to one embodiment of the present invention. [Figure 3] Figure 2 is an enlarged view of the linkage mechanism of the lawnmower shown. [Figure 4] This is a left side view showing the configuration of a lawnmower according to one embodiment of the present invention. [Figure 5] This is a rear view showing the configuration of a lawnmower according to one embodiment of the present invention. [Figure 6] Figure 4 is an enlarged view of the linkage mechanism of the lawnmower shown. [Figure 7] This is a left side view illustrating the forward and backward movement (position) of the left running section in conjunction with the relative vertical movement of the machine body relative to the running section according to one embodiment of the present invention. [Modes for carrying out the invention]

[0014] The lawnmower of the present invention will be described below with reference to the drawings. However, the lawnmower of the present invention can be implemented in many different forms and should not be interpreted as being limited to the examples shown below. In the drawings referenced in this embodiment, the same part or part having a similar function will be given the same reference numeral or the same reference numeral followed by an alphabet letter, and repeated explanations may be omitted. Also, if the same or similar members are provided on the left and right sides in the direction of travel, L (left-side member) or R (right-side member) will be added after the reference numeral of the member. If the left and right members are not particularly distinguished, L and R may be omitted in the explanation.

[0015] In one embodiment of the present invention, "up" indicates a direction vertically away from the ridge in a state where the lawn mower advances while performing a lawn mowing operation on the ridge, and "down" indicates a direction opposite to "up". For the sake of convenience in explanation, "front" indicates the direction in which the top surface mowing unit is located with respect to the traveling unit, and "rear" indicates a direction opposite to "front". Further, "left" or "right" indicates "left" or "right" with respect to the rear view of the lawn mower when viewed from the "rear" of the lawn mower.

[0016] Also, when taking the center line of the lawn mower in plan view (a line parallel to the traveling direction and passing through the center of the lawn mower) as a reference, relatively, the side closer to the center line is called "inner side", and the side farther from the center line is called "outer side".

[0017] <First Embodiment> [Configuration of Lawn Mower 100] The lawn mower 100 is a self-propelled lawn mower that performs a lawn mowing operation on the ridge while traveling. Specifically, it is a lawn mower that is remotely controlled by a remote controller and travels on the ridge to perform a lawn mowing operation.

[0018] The lawn mower 100 shown in FIGS. 1, 2, and 5 shows a state where the left traveling unit 20L is located lower than the right traveling unit 20R when the step on the left side of the top surface of the ridge is lower than the step on the right side of the top surface of the ridge. Further, the lawn mower 100 shown in FIGS. 1, 2, and 5 shows a state where the cutting surface 204L of the left side slope mowing unit 80L is parallel or substantially parallel to the horizontal plane 203, and the angle between 204R of the right side slope mowing unit 80R and the horizontal plane 203 is the angle α. FIG. 1 is a plan view showing the configuration of the lawn mower 100, FIG. 2 is a left side view showing the configuration of the lawn mower 100 in a state where the left traveling unit 20L is lower (than the right traveling unit 20R), FIG. 3 is an enlarged view around the link mechanism 50L shown in FIG. 2, FIG. 4 is a left side view showing the configuration of the lawn mower 100 in a state where the left traveling unit 20L is higher (than the right traveling unit 20R), and FIG. 5 is a rear view showing the configuration of the lawn mower 100. For the sake of easy understanding of the configuration of the present invention, in FIG. 2, some of the reference numerals shown in FIG. 3 are omitted.

[0019] In this embodiment, the cutting surfaces 204L and 204R are surfaces (FIG. 4) including the trajectories of the blades 82L (the grass cutting blades included therein) and 82R (the grass cutting blades included therein) of the left side surface cutting part 80L and the right side surface cutting part 80R for cutting grass, and the grass cutting blades may be called cutting blades.

[0020] As shown in FIG. 1, the lawn mower 100 includes a machine body 10, a control unit 16, left and right traveling parts 20L and 20R, left and right link mechanisms 50L and 50R, an engine 60, an alternator 70, a battery 40, and a cutting part 120 having a top surface cutting part 30 and a side surface cutting part 80. The driving of each part is controlled by the control unit 16. The lawn mower 100 can perform the grass cutting work on the top surface 201 and the side surface 202 of the ridge 200 in one pass by controlling the driving of the top surface cutting part 30 and the side surface cutting part 80 while self-propelling with the left and right traveling parts 20L and 20R.

[0021] The machine body 10 is a frame forming the skeleton of the lawn mower 100, and includes a machine body main body 14, a support plate 15 fixed to the machine body main body 14 and extending forward, and a link support plate (not shown) for supporting the left and right link mechanisms 50L and 50R fixed to the outside on the front side of the machine body main body 14. The support plate 15 is provided with top surface cutting part attachment parts 11L and 11R for attaching the top surface cutting part 30. Further, on the rear side of the machine body main body 14, side surface cutting part attachment parts 12L and 12R for connecting the side surface cutting part 80 are provided. Furthermore, on the side of the machine body main body 14, a first fixing member 57L for connecting the link mechanism 50L and a second fixing member 58L arranged forward of the first fixing member 57L are provided (details will be described later). Also, on the side of the machine body main body 14, in the same manner as the link mechanism 50L, a first fixing member (not shown) for connecting the link mechanism 50R and a second fixing member (not shown) for connecting the link mechanism 50R arranged forward of the first fixing member are provided. The machine body 10 can be configured using a metal material (for example, steel material, aluminum material), a fiber reinforced plastic (FRP) material, etc., but is not limited to this example.

[0022] The running sections 20L and 20R are a pair of left and right crawlers and function as the means of travel for the lawnmower 100. In a rear view, the running section 20L is the left-side running means in the direction of travel of the lawnmower 100, and the running section 20R is the right-side running means. Since the structure of the running section 20R is the same as that of the running section 20L, this explanation will mainly focus on the running section 20L.

[0023] As shown in Figure 2, the running section 20L includes a crawler belt 21L, drive wheels 22L, driven wheels 23L, a crawler frame 24L, and a drive unit 54L. The crawler belt 21L is stretched over the drive wheels 22L and driven wheels 23L and rotates in accordance with the rotation of the drive wheels 22L. The crawler belt 21L is made of an elastic material (specifically rubber) and has a plurality of lugs (protrusions). The drive unit 54L consists of a motor driven by power supplied from the alternator 70 and the battery 40. The drive wheels 22L rotate due to the power transmitted from the drive unit 54L. The power from the rotation of the drive wheels 22L is transmitted to the driven wheels 23L via the crawler belt 21L. The crawler frame 24L rotatably supports the drive wheels 22L and driven wheels 23L, respectively. In this embodiment, the running section 20L allows for adjustment of the ground contact length of the crawler belt 21L during pre-operation adjustments, but the ground contact length of the crawler belt 21L does not change during operation. A link mounting member 25L for connecting the running section 20L and the link mechanism 50L is fixed to the crawler frame 24L. The link mounting member 25L has a first mounting portion 25La and a second mounting portion 25Lb as mounting portions for attaching the first link arm 51L and the second link arm 52L, which will be described later. The first mounting portion 25La and the second mounting portion 25Lb are formed to protrude above the height position of the upper end surface of the running section 20L (crawler belt 21L).

[0024] As shown in Figure 2 or Figure 4, the linkage mechanisms 50L and 50R connect the machine body 10 to the running sections 20L and 20R, and relatively change the positional relationship between the machine body 10 and the running sections 20L and 20R, that is, the distance (spacing) between the machine body 10 and the running sections 20L and 20R, thereby having the function of moving the machine body 10 relatively between an upper limit position and a lower limit position with respect to the running sections 20L and 20R. The linkage mechanism 50L is the linkage mechanism on the left side in the direction of travel of the lawnmower 100 and is connected to the running section 20L. The linkage mechanism 50R is the linkage mechanism on the right side and is connected to the running section 20R. Since the structure of the linkage mechanism 50R is the same as that of the linkage mechanism 50L, the explanation here will focus on the linkage mechanism 50L.

[0025] The linkage mechanism 50L includes a first link arm 51L, a second link arm 52L, a plate link 56L, an electric cylinder 53L, and a movement assist mechanism 55L.

[0026] The configuration of the link mechanism 50L will be explained using Figure 2 or Figure 3. The first link arm 51L is a member formed in a substantially "L" shape (in side view), and has a first arm portion 51Ld extending in a first direction, a second arm portion 51Le intersecting with the first direction and extending in a direction different from the first direction, and a first bent portion 51Lb where the first arm portion 51Ld and the second arm portion 51Le intersect. The first bent portion 51Lb is rotatably connected to a first fixing member 57L fixed to the main body 14 (main body 10) by a first machine body side pivot shaft 62, and the first link arm 51L is rotatably connected to the main body 14 (main body 10) via the first bent portion 51Lb. The first end portion 51Lc (first end), which is the end of the first arm portion 51Ld, is rotatably connected by the first travel portion side pivot shaft 61 to the first mounting portion 25La of the link mounting member 25L, which is fixed to the crawler frame 24L. The second end portion 51La, which is the end of the second arm portion 51Le, is rotatably connected to the electric cylinder 53L.

[0027] The second link arm 52L is positioned in front of the first link arm 51L and, in a side view, is configured to be substantially the same shape (including identical shapes) as the first link arm 51L. The second link arm 52L, like the first link arm 51L, is a member formed in a substantially "L" shape (in a side view), and has a third arm portion 52Ld extending in a second direction, a fourth arm portion 52Le intersecting with the second direction and extending in a direction different from the second direction, and a second bend portion 52Lb where the third arm portion 52Ld and the fourth arm portion 52Le intersect. The end of the third arm portion 52Ld, the third end portion 52Lc (third end portion), is rotatably connected by a second running section side pivot shaft 71 to a second mounting portion 25Lb of a link mounting member 25L fixed to the crawler frame 24L. The second bent portion 52Lb is rotatably connected to the second fixing member 58L fixed to the main body 14 (main body 10) by the second machine body side pivot shaft 72, and the second link arm 52L is rotatably connected to the main body 14 via the second bent portion 52Lb. In this embodiment, the first direction and the second direction are the same (including substantially the same) direction, and the direction that intersects with the first direction and is different from the first direction, and the direction that intersects with the second direction and is different from the second direction are the same (including substantially the same) direction.

[0028] The plate link 56L is a plate-shaped member that connects the second arm portion 51Le of the first link arm 51L and the fourth arm portion 52Le of the second link arm 52L. For convenience, in this embodiment, the end of the second arm portion 51Le of the first link arm 51L will be called the second end portion 51La (second end portion), and the end of the fourth arm portion 52Le of the second link arm 52L will be called the fourth end portion 52La (fourth end portion). The plate link 56L is rotatably connected at its rear end to the second end portion 51La (second end portion) and at its front end to the fourth end portion 52La (fourth end portion). The connecting shaft between the plate link 56L and the second arm portion 51Le, and the connecting shaft between the electric cylinder 53L and the second arm portion 51Le, are on the same straight line in a side view. It has the function of maintaining a constant distance between the second end 51La of the first link arm 51L and the fourth end 52La of the second link arm 52L, and also assisting in keeping the aircraft body 10 and the link mechanism 50L horizontal (parallel).

[0029] The electric cylinder 53L functions as a power source for moving the main body 14 (main body 10) relative to the running section 20L using a link mechanism 50L, thereby moving the main body 14 and the running section 20L apart. One front end of the electric cylinder 53L is rotatably supported by a support bracket 53La located above and in front of the main body 14 (main body 10), and the other rear end is rotatably connected to the second arm portion 51Le of the first link arm 51L. In this embodiment, when the electric cylinder 53L is fully extended, the main body 14 and the running section 20L are furthest apart (see Figure 2), and the main body 10 is at its upper limit position relative to the running section 20L. When the electric cylinder 53L is fully retracted, the main body 14 and the running section 20L are closest together, and the main body 10 is at its lower limit position relative to the running section 20L (see Figure 4). In this embodiment, an electric cylinder 53L is used as an example of an actuator, but the actuator can be any configuration that allows the length between the support bracket 55Lc and the second arm portion 51Le to be changed. For example, the actuator may be a hydraulic cylinder.

[0030] The movement assist mechanism 55L is a mechanism for assisting the operation when the running section 20L is moved relatively away from the main body 14, that is, when the main body 14 is lifted and moved relative to the running section 20L. As shown in Figures 1 and 3, the movement assist mechanism 55L includes a holding member 55La that is roughly inverted "U" shaped in a top view and fixed to the fourth arm portion 52Le (between the fourth end portion 52La and the second bent portion 52Lb) of the second link arm 52L, a rod 55Lb that is fixed to the holding member 55La and extends forward, a support bracket 55Lc that is supported by the main body 14, an axial member 55Ld that is rotatably supported by the support bracket 55Lc and has a through hole formed therein for inserting the rod 55Lb, and a spring member 55Le that is interposed between the holding member 55La and the axial member 55Ld to connect them and through which the rod 55Lb is inserted. The spring member 55Le is made of a compression spring. When the main body 14 and the running section 20L are brought close together, that is, when the main body 14 is moved downward relative to the running section 20L, the fourth arm portion 52Le of the second link arm 52L rotates counterclockwise, and the spring member 55Le contracts. Conversely, when the main body 14 and the running section 20L are moved apart, that is, when the main body 14 is moved upward relative to the running section 20L, the fourth arm portion 52Le of the second link arm 52L rotates clockwise. At this time, a force is generated in the spring member 55Le that tends to extend, and this force acts as a force that assists the clockwise rotation of the fourth arm portion 52Le. Note that the spring member 55Le is not limited to a compression spring. Any material that acts as a force that assists the clockwise rotation of the fourth arm portion 52Le is acceptable, and it is also possible to use an elastic material such as a gas spring or rubber. In this embodiment, the mobility assist mechanism 55L may be referred to as an auxiliary means.

[0031] In this embodiment, one rear end of the electric cylinder 53L is rotatably connected to the second arm portion 51Le of the first link arm 51L, and the holding member 55La of the movement assist mechanism 55L is fixed to the fourth arm portion 52Le (between the fourth end portion 52La and the second bent portion 52Lb). However, one front end of the electric cylinder 53L may be rotatably connected to the fourth arm portion 52Le of the second link arm 52L, and the holding member 55La of the movement assist mechanism 55L may be fixed to the second arm portion 51Le (between the second end portion 51La and the first bent portion 51Lb). In other words, the electric cylinder 53L is connected to the main body 14 and to either the first link arm 51L or the second link arm 52L so that the first link arm 51L and the second link arm 52L can be rotated, and the movement assist mechanism 55L (holding member 55La) is connected to the main body 14 and to the other of the first link arm 51L or the second link arm 52L to which the electric cylinder 53L is not connected.

[0032] In this embodiment, a parallel link is formed by the first arm portion 51Ld of the first link arm 51L, the third arm portion 52Ld of the second link arm 52L, the link mounting member 25L, and the main body 14 (main body 10). Another parallel link is formed by the second arm portion 51Le of the first link arm 51L, the fourth arm portion 52Le of the second link arm 52L, the plate link 56L, and the main body 14 (main body 10). When the electric cylinder 53L is extended, the parallel link rotates clockwise (right), and the running section 20L moves away from the main body 14 (main body 10). On the other hand, when the electric cylinder 53L is retracted, the parallel link rotates counterclockwise (left), and the running section 20L moves closer to the main body 14 (main body 10).

[0033] Details regarding the operation of moving the running sections 20L and 20R relative to the main body 14 (main body 10) will be described later, but in the lawnmower 100, by extending and retracting the electric cylinders 53L and 53R to independently control and drive the parallel links, the link mechanisms 50L and 50R (running sections 20L and 20R) can be driven independently according to the difference in height of the top surface or the ground. As a result, when the running section 20L is lowered due to unevenness or steps in the ridges of the field, the link mechanism 50L is operated to move the main body 14 away from the running section 20L, moving the main body 14 upward relative to the running section 20L. Conversely, when the running section 20L is raised, the link mechanism 50L is operated to move the main body 14 closer to the running section 20L, moving the main body 14 downward relative to the running section 20L, thereby allowing the lawnmower 100 to run while maintaining a horizontal posture of the main body 14.

[0034] The link mechanism 50L is supported on a link support plate (body 10) (not shown) fixed to the main body 14 of the machine. The link mechanism 50L is arranged in parallel with the widest mount (engine 60 in this embodiment) mounted on the machine 10, so as to match the width of the widest mount, in order to make the width of the lawnmower 100 compact. At this time, as shown in Figure 2, etc., in a side view, the engine 60 is positioned to overlap with the electric cylinder 53L of the link mechanism 50L. However, in this embodiment, as shown in Figure 5, the movement assist mechanism 55L and the electric cylinder 53L are arranged in the order from the center outwards, so that the electric cylinder 53L is less affected (by heat, etc.) from the engine 60.

[0035] In this embodiment of the lawnmower 100, the first arm portion 51Ld of the first link arm 51L is configured to be longer than the length of the second arm portion 51Le when viewed from the side, but this is not the case. The lengths of the first arm portion 51Ld and the second arm portion 51Le can be appropriately changed considering the force required to lift the travel section 20L and the stroke length of the electric cylinder 53L, and it is also possible to configure the first arm portion 51Ld to be shorter than the second arm portion 51Le. Furthermore, the intersection angle (angle of the first bend portion 51Lb) between the first arm portion 51Ld and the second arm portion 51Le can also be appropriately changed. The lengths of the third arm portion 52Ld and the fourth arm portion 52Le of the second link arm 52L, as well as the angle of the second bend portion 52Lb, are the same as those of the first link arm 51L.

[0036] Let us return to Figure 1, Figure 2, or Figure 4 to continue the explanation. As shown in Figure 1, Figure 2, or Figure 4, the control unit 16 is located, for example, above and behind the machine body 10 and has the function of controlling the travel unit 20, the cutting unit 120, and the battery 40. The control unit 16 has an electronic circuit board equipped with, for example, a computing device, memory, and communication circuits. For example, the memory stores control programs for controlling various parts of the grass cutter 100, the computing device reads the control programs from the memory and controls the travel unit 20, the link mechanisms 50L and 50R, and the top cutting unit 30 and the slope cutting unit 80 based on the control programs. Although not shown in the diagram, the main body 14 of the lawnmower 100 is equipped with an IMU (Inertial Measurement Unit) for detecting the attitude of the main body 14. The control unit 16 controls the drive of the electric cylinders 53L and 53R based on the attitude of the main body 14 detected by the IMU, thereby maintaining the attitude of the main body 14 (main body 10) horizontally.

[0037] The engine 60 is located above and in front of the machine body 10. The engine 60 functions as a power source for the drive units 33L and 33R that drive the blades 32L and 32R included in the top surface cutting unit 30, and as a power source for the alternator 70. The power generated by the engine 60 is transmitted to the drive units 33L and 33R, and to the separately provided alternator 70, via a power transmission means (not shown) consisting of a belt or the like. The power transmission means includes, for example, a first power transmission means (not shown) for transmitting power to the alternator 70 and a second power transmission means (not shown) for transmitting power to the top surface cutting unit 30.

[0038] The alternator 70 is positioned, for example, above the support plate 15. A belt (not shown) of a first power transmission means is stretched between the alternator 70 and the engine 60. Power from the engine is transmitted via the belt, causing the alternator 70 to generate electricity. The alternator 70 supplies the generated electricity to the battery 40 and also functions as a power source for the drive units 83L and 83R that drive the blades 82L and 82R included in the slope mowing unit 80, and the drive units 54L and 54R that drive the travel unit 20. The electricity generated by the alternator 70 is also supplied to the drive units 83L and 83R, drive units 54L and 54R, drive units 33L and 33R, and the battery 40 via a power supply means (not shown) that supplies power and / or control signals (electrical signals), such as a wire harness or harness cable.

[0039] The alternator 70 is equipped with a power generation control circuit (not shown) for controlling power generation. The brush cutter 100 is equipped with a sensor (not shown) for detecting battery voltage, and the power generation control circuit monitors the results detected by the sensor, allowing the alternator 70 itself to control the power generation state. The power generation control circuit monitors the battery voltage and controls the alternator 70 so that it generates power and supplies power when the battery voltage falls below a predetermined value, and stops supplying power when the battery voltage exceeds the predetermined value.

[0040] The battery 40 is located, for example, above the machine body 10 and between the engine 60 and the control unit 16. The battery 40 stores the electricity generated by the alternator 70. The battery 40 functions as a power source that supplies the stored electricity to the drive units 83L and 83R (see Figure 1, 2, or 3) that drive the blades 82L and 82R included in the slope mowing unit 80, and to the drive units 54L and 54R (see Figure 1, 2, or 3) that drive the running unit 20 back and forth. The battery 40 also functions as a power source that supplies the stored electricity to the electric cylinders 53L and 53R that operate the link mechanisms 50L and 50R that change the vertical positional relationship between the machine body 10 and the running unit 20. The power stored in the battery 40 is supplied to the drive units 83L and 83R, the drive units 54L and 54R, and the electric cylinders 53L and 53R via a power supply means similar to that of the alternator 70.

[0041] The lawnmower 100 may include a cover member. The cover member serves to cover and protect the control unit 16, battery 40, alternator 70, and engine 60. The cover member may also be configured to cover only a portion of the control unit 16, battery 40, alternator 70, and engine 60.

[0042] Next, the mowing unit 120 will be described using Figures 1, 2, 4, or 5. The mowing unit 120 has a top mowing unit 30 located in front of the traveling unit 20 and a slope mowing unit 80 located behind the traveling unit 20. In this embodiment, the top mowing unit 30 is positioned in the direction in which the machine body 10 moves (forward) and functions as a mowing means for cutting weeds and other grass growing on the ridges. The slope mowing unit 80 is positioned 180 degrees opposite to the direction in which the machine body 10 moves (rear) and functions as a mowing means for cutting weeds and other grass growing on the ridges. In the mower 100, the slope mowing unit 80 may be located in front of the traveling unit 20 and the top mowing unit 30 may be located behind the traveling unit 20. In this case, left and right correspond to left and right when viewed from the front.

[0043] The top cutting section 30 includes a casing 31, two blade sections 32L and 32R arranged side by side, and drive sections 33L and 33R. The drive sections 33L and 33R are connected to the top cutting section mounting sections 11L and 11R. The casing 31 covers the top and sides of the blade sections 32L and 32R to prevent soil, pebbles, grass, etc. from scattering into the surrounding area. Since the structure of the blade section 32L and the drive section 33L is the same as the structure of the blade section 32R and the drive section 33R, this explanation will focus on the blade section 32R and the drive section 33R.

[0044] As shown in Figures 2, 4, or 5, the blade section 32R has multiple grass-cutting blades. The blade section 32R is connected to the rotating shaft of the drive unit 33R and rotates with power from the engine 60. The rotation of the rotating shaft of the drive unit 33R also rotates the multiple grass-cutting blades, and the blade section 32R is configured to cut grass. The drive unit 33R has a second power transmission means (not shown) including a belt (not shown) that transmits power from the engine 60 to the blade section 32R.

[0045] In this embodiment, the blade sections 32L and 32R are provided symmetrically or substantially symmetrically with respect to the center line 110 of the machine body 10, and are arranged with a phase difference so as not to interfere with each other when stationary. The second power transmission means is designed to transmit the driving force of the engine 60, transmitted via a belt, equally or substantially equally to both the drive units 33L and 33R. Therefore, the multiple grass-cutting blades of blade section 32L and the multiple grass-cutting blades of blade section 32R rotate at the same timing and speed.

[0046] In the lawnmower 100, an example is shown in which an engine 60 is used as the power source for rotating the blade portion 32 of the top cutting section 30. However, it is also possible to use a motor as the power source for rotating the blade portions 32L and 32R, not limited to the example described here. In this case, a control unit may be used to independently control the drive units 33L and 33R and drive the blade portions 32L and 32R independently.

[0047] The slope mowing section 80 includes a left slope mowing section 80L and a right slope mowing section 80R. Also, as shown in Figure 1, the grass mower 100 has a pair of left and right slope mowing section mounting sections 12L and 12R, and a pair of left and right angle adjustment mechanisms 130L and 130R. The rear ends of the main body 14 (body 10) of the grass mower 100 are the rear left end 17L and the rear right end 17R, which are symmetrical or approximately symmetrical with respect to the center line 110.

[0048] The left slope mowing section 80L and the right slope mowing section 80R each include casings 81L and 81R, blade sections 82L and 82R, drive sections 83L and 83R, slope mowing section support sections 89L and 89R, and handles 140L and 140R, respectively. The blade sections 82L and 82R have multiple grass-cutting blades, similar to the blade sections 32L and 32R of the top surface mowing section 30, and the grass growing on the ridge is cut by the rotation of the blade sections 82L and 82R, which have multiple grass-cutting blades. Since the structure of the left slope mowing section 80L is the same as the structure of the right slope mowing section 80R, the explanation here will focus on the right slope mowing section 80R.

[0049] The right-side slope mowing section 80R is connected to the rear right end 17R via the slope mowing section mounting section 12R, the angle adjustment mechanism 130R, and the slope mowing section support section 89R.

[0050] The slope mowing support section 89R is attached to the casing 81R. The casing 81R is connected to the angle adjustment mechanism 130R via the slope mowing support section 89R. The casing 81R covers the blade section 82R and, like the casing 31 of the top surface mowing section 30, prevents soil, pebbles, grass, etc. from scattering to the surroundings. A handle 140R is attached to the casing 81R. The handle 140R serves as a gripping part when adjusting the angle of the right-side slope mowing section 80R. The drive unit 83R is connected to the blade section 82R and is the part for rotating the blade section 82R, and has a motor that is driven by power supplied from the alternator 70 and the battery 40. In this embodiment, the casing 81R may be called the cover section, and the blade section 82R that is not covered by the casing 81R faces the ridge 200.

[0051] In the lawnmower 100, the drive units 83L and 83R are independently controlled using the control unit 16. The drive units 83L and 83R supply power from the alternator 70 or battery 40 to the blade units 82L and 82R.

[0052] The angle adjustment mechanism 130 (130L and 130R) can adjust the positions of the left slope mowing section 80L and the right slope mowing section 80R in advance according to the width of the top surface 201 of the ridge 200, and then independently adjust the angle α between the mowing surface 204L or 204R and the horizontal surface 203 to match the positions of the left slope mowing section 80L and the right slope mowing section 80R (see Figure 5). Since the structure of the angle adjustment mechanism 130L is the same as that of the angle adjustment mechanism 130R, the explanation here will focus on the angle adjustment mechanism 130R using Figure 5.

[0053] The angle adjustment mechanism 130R includes, for example, a lock plate 131R, a slope mowing section mounting pin 132R, and an angle adjustment pin 133R. The angle adjustment mechanism 130R is connected between the slope mowing section mounting section 12R and the slope mowing section support section 89R using the slope mowing section mounting pin 132R, and is rotatably connected to the slope mowing section mounting section 12R and the slope mowing section support section 89R. The angle adjustment pin 133R is inserted through an insertion hole formed in the slope mowing section support section 89R and is fixed in the insertion hole. The lock plate 131R has a plurality of positioning recesses 131Ra (four in this embodiment) that engage with the angle adjustment pin 133R to position and fix the angle of the mowing surface 204R.

[0054] Referring to Figure 5, the angle adjustment operation of the right slope mowing unit 80R using the angle adjustment mechanism 130R will be explained. Holding the handle 140R, the right slope mowing unit 80R is operated to move it so that the angle adjustment pin 133R is disengaged from the positioning recess 131Ra. At this time, the slope mowing unit support 89R rotates together with the angle adjustment pin 133R relative to the slope mowing unit mounting 12R and the lock plate 131R. By inserting the angle adjustment pin 133R into a positioning recess 131Ra that is different from the positioning recess 131a that it was initially fitted into, the angle α between the mowing surface 204R and the horizontal surface 203 can be changed.

[0055] In this embodiment, when the angle adjustment pin 133R is fitted into the leftmost positioning recess 131Ra in a rear view of the grass cutter 100 (Figure 5), the angle α becomes 90 degrees, that is, the cutting surface 204R becomes perpendicular or approximately perpendicular to the horizontal plane 203. When the angle adjustment pin 133R is fitted into the rightmost positioning recess 131Ra, the angle α becomes 180 degrees, that is, the cutting surface 204R becomes parallel or approximately parallel to the horizontal plane 203. The state where the angle α is 180 degrees corresponds to the state of the left slope cutting section 80L shown in Figures 1, 2, 4, and 5.

[0056] As shown in Figures 1, 2, 4, and 5, the grass cutter 100 can perform grass cutting by adjusting the angle α between the cutting surfaces 204L and 204R and the horizontal plane 203 asymmetrically (to different angles). Although not shown in the figures, it is also possible to perform grass cutting with the angle α between the cutting surfaces 204L and 204R and the horizontal plane 203 adjusted symmetrically.

[0057] [Example of an action to move the aircraft 10 up and down] Figures 3, 6, and 7 will be used to explain the vertical movement of the machine body 10 (body 14) of the lawnmower 100. Since the structure of the link mechanism 50R is the same as that of the link mechanism 50L, we will focus on the link mechanism 50L here and explain the forward and backward movement (position) of the running section 20L that accompanies the relative vertical movement of the machine body 10 (body 14) relative to the running section 20L. Figure 6 is a left side view illustrating the state when the body 14 of the lawnmower 100 has moved to its lowest position relative to the left running section 20L, and Figure 7 is a left side view illustrating the vertical movement of the machine body 10 relative to the left running section 20L of the lawnmower 100 and the resulting forward and backward movement (position) of the machine body 10.

[0058] As described above, the parallel link is formed by the first link arm 51L, the second link arm 52L, the link mounting member 25L, and the main body 14. The electric cylinder 53L has one end fixed to the main body 14 (support bracket 55Lc) and the other end connected to the second arm portion 51Le (second end portion 51La) of the first link arm 51L. The spring member 55Le of the movement assist mechanism 55L has one end fixed to the main body 14 (support bracket 55Lc) and the other end connected to the fourth arm portion 52Le of the second link arm 52L. The plate link 56L connects the second arm portion 51Le of the first link arm 51L and the fourth arm portion 52Le of the second link arm 52L.

[0059] Figure 6 shows a state where the relative positions of the running section 20L and the aircraft body 10 are close together, and the vertical position of the aircraft body 10 relative to the running section 20L is lower than the vertical position of the aircraft body 10 shown in Figure 3. Here, we will explain using the state in which the vertical position of the aircraft body 10 is at its lowest position (lower limit) as shown in Figure 6 and the state in which it is at its highest position (upper limit) as shown in Figure 3 as examples. In Figure 7, the running section 20L etc. shown by the dotted line shows the state in which the relative positions of the running section 20L and the aircraft body 10 are closest as shown in Figure 6, i.e., the state in which the aircraft body 10 is at its lowest position, and the running section L etc. shown by the solid line shows the state in which the relative positions of the running section 20L and the aircraft body 10 are farther apart as shown in Figure 3, i.e., the state in which the aircraft body 10 is at its highest position.

[0060] Figure 6 illustrates the driving state of the grass cutter 100 when there is a protruding step on the left side of the top surface of the ridge. When the grass cutter 100 drives over the protruding step on the left side of the top surface of the ridge, the machine body 10 tilts upward to the left along with the driving unit 20L. The IMU detects this tilt, and according to the detection result, the control unit 16 sends a signal to the electric cylinder 53L to control the machine body 10 to move downward. As a result, the electric cylinder 53L retracts and rotates the link mechanism 50L counterclockwise relative to the machine body 10. At this time, the first link arm 51L rotates counterclockwise around the first machine body side pivot axis 62, and the second link arm 52L rotates counterclockwise around the second machine body side pivot axis 72. As a result, the driving unit 20L and the machine body 10 come closer together according to the amount of the step in the ridge, and the machine body 10 moves downward.

[0061] Figure 3 illustrates the driving state of the grass cutter 100 when there is a step on the left side of the top surface of the ridge. When driving over a step on the left side of the top surface of the ridge, the machine body 10 tilts downward to the left along with the driving unit 20L. The IMU detects this tilt, and according to the detection result, the control unit 16 sends a signal to the electric cylinder 53L to control the machine body 10 to move upward. As a result, the electric cylinder 53L extends and rotates the link mechanism 50L clockwise relative to the machine body 10. At this time, the first link arm 51L rotates clockwise around the first machine body side pivot axis 62, and the second link arm 52L rotates clockwise around the second machine body side pivot axis 72. As a result, the driving unit 20L and the machine body 10 separate according to the amount of the step in the ridge, and the machine body 10 moves upward.

[0062] In this embodiment, the spring member 55Le of the movement assist mechanism 55L expands and contracts as the second link arm 52L rotates. When the machine body 10 is lowered toward the running section 20L, the link mechanism 50L rotates counterclockwise relative to the machine body 10, causing the fourth arm portion 52Le of the second link arm 52L to contract the spring member 55Le. When the machine body 10 is raised away from the running section 20L, the force of the contracted spring member 55Le attempting to extend acts as a force that attempts to rotate the link mechanism 50L (fourth arm portion 52Le) clockwise. Therefore, when raising the machine body 10 relative to the running section 20L, in addition to the thrust of the electric cylinder 53L, the force of the spring member 55Le of the movement assist mechanism 55L can also be used as a force to rotate the link mechanism 50L, allowing the use of a relatively small (low thrust) electric cylinder 53L.

[0063] When raising the machine body 10 relative to the running section 20L, a force is required to lift the machine body 10 against the weight of the machine body 10 and its load. In the lawnmower 100 of this embodiment, in addition to the thrust of the electric cylinder 53L, the force of the spring member 55Le of the movement assist mechanism 55L can also be used as a force to lift the machine body 10 (a force that rotates the link mechanism 50L), so a relatively small (low thrust) electric cylinder 53L can be used. Furthermore, the extension speed of the electric cylinder 53L may be slow depending on the load that needs to be driven by extension, but in the lawnmower 100, the extension of the electric cylinder 53L can be assisted by using the spring member 55Le. As a result, the lawnmower 100 can maintain a stable horizontal position of the machine body 10.

[0064] By the way, when the link mechanism 50L is rotated to keep the machine body 10 horizontal while it is moving, the running section 20L also rotates. As a result, the running section 20L not only moves relative to the machine body 10 (moves vertically), but its position in the front-to-back direction relative to the machine body 10 also changes. The lawnmower 100 of this embodiment is operated remotely using a remote controller, but if the (relative) positional relationship between the running section 20L and the machine body 10 changes significantly during operation, the user's feel of operating the remote controller will change, which may cause discomfort to the user. Therefore, in the lawnmower 100 of this embodiment, even if the running section 20L is rotated by the link mechanism 50L to control the horizontal position of the machine body 10 while it is moving, the relative front-to-back position of the running section 20L relative to the machine body 10 does not change significantly.

[0065] This will be explained in detail using Figure 7. As shown in Figure 7, in a side view, in this embodiment, when the machine body 10 is at the lower limit position, the first end 51Lc (first end) of the first link arm 51Ld (first arm portion 51Ld) is located above the horizontal plane 111 passing through the first machine body-side pivot axis 62, which is the pivot point of the first link arm 51L (first arm portion 51Ld) relative to the machine body 10. When the machine body 10 is at the upper limit position, the first end 51Lc (first end) of the first arm portion 51Ld is located below the horizontal plane 111. In other words, when the machine body 10 is moved from the lower limit position to the upper limit position, the first machine body-side pivot axis 62 is located between the position where the first end 51Lc is highest and the position where the first end 51Lc is lowest in the height direction. In other words, when the machine body 10 is moved from the lower limit position to the upper limit position, there is a state in which the first arm portion 51Ld is horizontal (parallel to the horizontal plane 111).

[0066] When moving the aircraft 10 from the lower limit position to the upper limit position, the running unit 20L moves backward as the first arm 51Ld rotates when the first end portion 51Lc is above the horizontal plane 111. When the first arm 51Ld becomes horizontal, the running unit 20L is in its rearmost position (relative to the aircraft). Furthermore, as the rotation of the first arm 51Ld progresses and the first end portion 51Lc is positioned below the horizontal plane 111, the direction of movement of the running unit 20L reverses, and the running unit 20L moves forward as the first arm 51Ld rotates.

[0067] In this way, by rotating the first arm portion 51Ld so as to straddle the horizontal plane 111, the direction of movement of the running portion 20L in the front-rear direction can be reversed across the horizontal plane 111. That is, when the first arm portion 51Ld rotates, the amount of movement of the running portion 20L before and after passing the horizontal plane 111 can be canceled out, and the change in the relative front-rear position of the running portion 20L with respect to the machine body 10 can be kept to a minimum.

[0068] In this embodiment, the angle between the first arm portion 51Ld and the horizontal plane 111 at the upper limit position of the machine body 10 is approximately the same as the angle between the first arm portion 51Ld and the horizontal plane 111 at the lower limit position of the machine body 10. Therefore, as shown in Figure 7, the longitudinal position of the running unit 20L at the upper and lower limit positions of the machine body 10 changes by only a small distance (distance D2), and the overall amount of movement D3 is also small. The overall amount of longitudinal movement D3 of the running unit 20L is smallest when the angle between the first arm portion 51Ld and the horizontal plane 111 at the upper limit position of the machine body 10 is equal to the angle between the first arm portion 51Ld and the horizontal plane 111 at the lower limit position of the machine body 10. However, how these angles are set can be adjusted as appropriate. The angle may be set such that the amount of movement of the traveling section 20L when the first arm section 51Ld is above the horizontal plane 111 is greater than the amount of movement when the first arm section 51Ld is below the horizontal plane 111, or it may be set so that it is smaller.

[0069] Here, the function of the plate link 56L will be explained. As described above, in the lawnmower 100 of this embodiment, when the machine body 10 is moved from the lower limit position to the upper limit position, there is a state in which the first arm portion 51Ld is parallel to the horizontal plane 111. At this time, the third arm portion 52Ld of the second link arm 52L is also parallel to the horizontal plane 111, and the parallel link (first parallel link) composed of the first arm portion 51Ld, the third arm portion 52Ld, the link mounting member 25L, and the machine body 14 (machine body 10) becomes unstable. Therefore, in the lawnmower 100 of this embodiment, the second end 51La (second end) of the second arm portion 51Le of the first link arm 51L and the fourth end 52La (fourth end) of the fourth arm portion 52Le of the second link arm 52L are connected by a plate link 56L, and the link mechanism 50L is provided with a parallel link (second parallel link) separate from the first parallel link consisting of the second arm portion 51Le, the fourth arm portion 52Le, the plate link 56L and the machine body 14 (machine body 10).

[0070] When the first arm portion 51Ld and the third arm portion 52Ld are parallel to the horizontal plane 111, the second arm portion 51Le and the fourth arm portion 52Le are not parallel to the horizontal plane 111. Therefore, even if the first parallel link becomes unstable when the first arm portion 51Ld and the third arm portion 52Ld are parallel to the horizontal plane 111, the rotational movement of the link mechanism 50 can be stably maintained by the second parallel link.

[0071] As described above, the lawnmower 100 according to one embodiment of the present invention, by having the above configuration, can suppress the amount of front-to-back positional movement associated with the vertical movement of the traveling sections 20L and 20R. As a result, even if there is a slope or step on the top surface of the ridge, the user can operate the lawnmower 100 without any discomfort due to the amount of front-to-back positional movement associated with the vertical movement of the traveling sections 20L and 20R. Furthermore, even if there is a slope or step on the top surface of the ridge, the lawnmower 100 can travel stably on the ridge and perform grass cutting work without tilting and losing balance.

[0072] Although the lawnmower 100 of the present invention has been described above with reference to the drawings, the present invention is not limited to the embodiments described above, and can be modified as appropriate without departing from the spirit of the invention. For example, by changing the layout of the electric cylinder and adjusting the connection position between the electric cylinder and the link mechanism, the shape of the first link arm and the second link arm can be changed from an "L" shape with a bent portion to a straight shape. Thus, even if a person skilled in the art adds, deletes, or modifies components as appropriate based on each embodiment, it is included in the scope of the present invention as long as it retains the gist of the invention. Furthermore, the configurations of each embodiment described above can be combined as appropriate as long as they do not contradict each other, and technical matters common to each embodiment are included in each configuration even if not explicitly described.

[0073] Any effects or benefits other than those brought about by the embodiments described above, if they are clear from the description herein or easily predictable to a person skilled in the art, are naturally considered to be brought about by the present invention. [Explanation of Symbols]

[0074] 10: Machine body, 11L: Top surface mowing section mounting section, 11R: Top surface mowing section mounting section, 12L: Slope mowing section mounting section, 12R: Slope mowing section mounting section, 14: Machine body, 15: Support plate, 16: Control unit, 17L: Rear left end, 17R: Rear right end, 20L: Running section, 20R: Running section, 21L: Crawler belt, 21R: Crawler belt, 22L: Drive wheel, 22R: Drive wheel, 23L: Driven wheel, 23R: Driven wheel, 24L: Crawler frame, 24R: Crawler frame, 25L: Link mounting member, 25La: First mounting section, 25Lb: Second mounting section, 25R: Link Mounting member, 30: Top cutting section, 31: Casing, 32: Blade section, 32L: Blade section, 32R: Blade section, 33L: Drive unit, 33R: Drive unit, 40: Battery, 50L: Link mechanism, 50R: Link mechanism, 51L: First link arm, 51R: First link arm, 51La: Second end, 51Lb: First bend, 51Lc: First end, 51Ld: First arm section, 51Le: Second arm section, 52L: Second link arm, 52R: Second link arm, 52La: Fourth end, 52Lb: Second bend, 52Lc: Third end, 52Ld: Third arm section, 52Le: Fourth arm 53L: Electric cylinder, 53R: Electric cylinder, 54L: Drive unit, 54R: Drive unit, 55L: Movement assist mechanism, 55La: Holding member, 55Lb: Rod, 55Lc: Support bracket, 55Ld: Shaft-shaped member, 55Le: Spring member, 56L: Plate link, 56R: Plate link, 57L: First fixing member, 58L: Second fixing member, 60: Engine, 61: First drive unit side pivot shaft, 62: First machine body side pivot shaft, 70: Alternator, 71: Second drive unit side pivot shaft, 72: Second machine body side pivot shaft, 80: Slope mowing unit, 80L: Left slope mowing unit, 80R: Right slope 81L: Casing, 81R: Casing, 82L: Blade, 82R: Blade, 83L: Drive unit, 83R: Drive unit, 89L: Slope mowing unit support, 89R: Slope mowing unit support, 100: Mower, 110: Centerline, 111: Horizontal plane, 120: Mowing unit, 130: Angle adjustment mechanism, 130L: Angle adjustment mechanism, 130R: Angle adjustment mechanism, 131L: Lock plate, 131La: Positioning recess, 131R: Lock plate, 131Ra: Positioning recess, 132L: Slope mowing unit mounting pin, 132R: Slope mowing unit mounting pin, 133L: Angle adjustment pin,133R: Angle adjustment pin, 140L: Handle, 140R: Handle, 200: Ridge, 201: Top surface, 202: Slope, 203: Horizontal surface, 204L: Mowing surface, 204R: Mowing surface,

Claims

1. It is a grass cutter that cuts grass while driving along the edge of a field, The aircraft and, The running gear and A connecting part that is rotatably connected to the machine body and whose end is rotatably connected to the running part, and which rotates relative to the machine body, thereby moving the running part relative to the machine body, An actuator that rotates the aforementioned connecting portion, Equipped with, The aforementioned connecting portion is A first link arm is rotatably connected to the aforementioned machine body, A second link arm is rotatably connected to the aforementioned aircraft body, A link member connecting the first link arm and the second link arm, Equipped with, The actuator is connected to either the first link arm or the second link arm, A lawnmower in which, when the connecting portion is rotated relative to the machine body, the end of the connecting portion is movable upward and downward of the machine body.

2. The connecting portion is connected to the machine body using a first pivot shaft that is rotatably connected to the machine body. The lawnmower according to claim 1, wherein when the connecting portion is rotated relative to the machine body, the first pivot axis is located in the height direction between the upper rotation position and the lower rotation position of the end of the connecting portion.

3. The first link arm includes a first arm portion, one end of which is rotatably connected to the machine body on the first pivot axis and the other end of which is rotatably connected to the running portion, The second link arm is rotatably connected at one end to the machine body on the second pivot axis and rotatably connected at the other end to the running section, and includes a third arm section positioned in front of the first arm section. The ends of the connecting portion are the other end of the first arm portion and the other end of the third arm portion. The lawnmower according to claim 2, wherein when the first arm is rotated about the first pivot axis as the pivot point, the first pivot axis is located in the height direction between the upper rotation position and the lower rotation position of the other end of the first arm.

4. The first link arm has a second arm portion extending in a direction other than the first direction from one end, which is connected to the first pivot axis of the first arm portion extending in the first direction, The lawnmower according to claim 3, wherein the second link arm has a fourth arm portion extending in a direction different from the second direction from one end, which is connected to the second pivot axis of the third arm portion extending in the second direction.

5. The lawnmower according to claim 4, wherein the link member connects the end of the second arm portion opposite to the first pivot axis and the end of the fourth arm portion opposite to the second pivot axis.

6. One end is connected to the machine body, and the other end is connected to the first link arm or the second link arm to which the actuator is not connected. The lawnmower according to claim 5, further comprising an auxiliary means for assisting the movement of the traveling part relative to the machine body by the actuator.

7. The actuator is connected to the first link arm, The lawnmower according to claim 6, wherein the auxiliary means is connected to the second link arm.

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